87
rate, though twice as large here, was still acceptable at 8 percent,
and a small increase for crop/pasture. The correspondences of the
forest, crop/pasture, and water categories were in excellent agreement
0> 95 percent), as before, with the (P' + S') adjustment. Impres
sively, LDR, which formerly was associated with a 97 percent error
rate, was reduced to less than a 5 percent disagreement by the
(P* + S') adjustment. And the 30 percent error rate for the CII cate
gory was reduced to an acceptable 8 percent. The transitional category
was also much improved, from 33.5 to 15.2 percent error.
Comparison of the MAGI statistics for P and (P* + S') revealed that
reassignments made as P was adjusted to (P’ + S') for each cover type
were: +2.9 percent for forest, -12.7 percent for crop/pasture, -50.0
percent for water, -15.9 percent for transitional, -2.9 percent for
CII, +4.6 percent for MDR, and +13.1 percent for LDR. The most notable
differences between these figures and those computed for the whole area
were associated with the downward adjustments to the transitional and
CII categories of 8 and 3 times former adjustments respectively.
Optimal MAGI System/Landsat Data Correspondence
The results from Tables I and II are summarized in Table III where the
computation options for the MAGI System data were ranked in order of
determination complexity. From this analysis, neither the P nor P'
options, whether for the whole area or the more cover-specific subarea,
provide the required minimum level of accuracy 0> 90 percent). The
adjusted data (P' + S') were required in general, and specific land use
labels were required to achieve high correspondence for CII and LDR and
near acceptable correspondence for the transitional category.
Spatial Degradation of Landsat Data
The results of resampling the Landsat data used in Table II (the 85
percent subarea) to produce a spatially degraded product (L R ) of the
same grid cell size as the MAGI 4.6 acre data base were: forest,
36,790 acres (58.4 percent); crop/pasture, 7,944 acres (12.6 percent);
water, 63 acres (0.1 percent); transitional, 602 acres (1.0 percent);
CII, 4,623 acres (7.3 percent); MDR, 9,278 (14.7 percent); and LDR,
3,684 acres (5.8 percent). These results were compared with the
earlier full resolution Landsat data (L ), and with the MAGI data (M).
F
The resampling of the 1.54 acre Landsat data to 4.6 acre cells created
a significant degradation in correspondence between the original Land
sat data and the MAGI data, as shown in Tables IV and V. CII and LDR
were the only categories to maintain a reasonable correspondence
between the original and resampled Landsat data sets (Lj,:L^). Good
correspondence occurred in the MDR and LDR categories for the L^:M com
parison, but only for the P level of MAGI data, a consequence of
removing information content in the degradation process. A similar
pattern exists for the L :L and L :M comparisons: error rates in the
F R R
15-20 percent range for forest, crop/pasture, and water and in excess
of 40 percent for transitional. This similarity is not surprising
given the good correspondence of L :M.
r
DISCUSSION
The results indicate that for good correspondence of the Landsat and
MAGI System data for the seven land cover categories examined here, the
(P' + S') information level from the MAGI System is preferred for esti
mating all cover types. The computation of (P' + S') is especially